


Testament of a DxD

by Tohka_Yatogami



Category: Highschool DxD (Anime), 新妹魔王の契約者 | Shinmai Maou No Testament | The Testament of Sister New Devil - All Media Types
Genre: Multi
Language: English
Status: Completed
Published: 2019-01-25
Updated: 2019-04-26
Packaged: 2019-12-30 21:15:58
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 12,948
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18322148
Author URL: https://archiveofourown.org/users/Tohka_Yatogami/pseuds/Tohka_Yatogami
Summary: (Imported Work from fanfiction.net)Issei Hyoudou always dreamed of being a Harem King, so when a girl his age ends up living with him, he quickly believes that chance has come. Unfortunately, it quickly becomes evident that this chance at love is too good to be so easy... for none of the reasons he'd expect. Will he survive the challenge of protecting Mio Naruse, or pay the ultimate sacrifice? (Issei/Mio/Rias/Harem)





	1. Chapter 1

**Author's Note:**

> This is part of my unfinished works, which I stopped doing because I had trouble planning for a story with mature-level violence.

**Alright, take two with this story. Hopefully this first chapter works out better than the original did. Anyways, for anyone new to this story? I welcome you all to the second version of "Testament of a DxD!" For those who are curious about what they can expect, here's a little spoiler free rundown of how DxD and Testament/Shinmai will show up in this story.**

**I'll be including and excluding things and characters from both series, depending on everyone/everything I can or can't work in, but I'm going to try using all that I can without making things too messy. For which series is more dominant, I'm not far enough in to know that just yet, especially since I only started the story around this time because I'm slumping on my DxD trilogy and need a slight break from it.**

**I will say there are three characters being excluded from the start along with one change from Shinmai/Testament, ones that are obvious to anyone that's seen at least the first two episodes of both their respective anime adaptions. Said exclusions are Basara and both of Issei's parents, for reasons that I won't say because this chapter will answer that.**

**The harem's size is currently unknown, as the many options to make a DxD harem with makes me worried about overdoing it, so I'm giving myself a limit cap of 10 people. If things work out, then I'll raise the cap, but I ask no one try to request any harem additions for that reason. Finally, there are some scenes in this story you'll only see on Archive of Our Own, so look for "Testament of a DxD: Extras" on there when this story reaches such a point.**

**Well, I have nothing else to say, so... let's give this crossover the green light for the second time!**

* * *

**()**  - Albion Talking via the Divine Dividing

 **[]**  - Ddraig Talking via the Boosted Gear

 **{}**  - Consciousness of any other Sacred Gear Talking

 **〖〗**  - Voice Speaking through a Magic Circle

 **【】**  - Voice made by an Announcement or through an Announcer

『』 - Electrical Voice or Machine Speaking

 **「」**  - Insert Song Beginning or Ending

* * *

**_Chapter 1 - Red Revolution_ **

An inhuman roar shot through some unknown area, causing a girl with red hair and red eyes to run away in fear, wearing nothing but two black ribbons and a brown cloak over her otherwise naked form.

"Don't let her escape!" A loud voice ordered, nearly demanding it.

At that moment, the girl turned around to see something that could only be seen as black shadows the area, rushing towards her with the intent to capture her... by any means necessary.

"We've found her!" One of them shouted.

"Get her!" A second exclaimed.

"Get away from me!" She screamed, throwing a hand out.

A powerful burst released from it, causing a huge cloud of dark red smoke to envelop the area. She didn't even bother to confirm their destruction as she kept running away.

Her choice to not look back was founded as more of whatever was chasing after her joined up with the initial duo.

'Please, help me... mommy!' She begged, closing her eyes as she kept running.

As the chasing force behind her got close, a silhouette (or maybe more) suddenly collided with the retrieval force and flung them across the room.

"Huh?" She blinked, looking at the sight.

At that moment, she felt someone grab her hand, noticing a young girl with long silver hair and purple eyes was the culprit.

"Maria?" She stated, recognizing her.

"Mio, follow me. Hurry!" Maria whispered.

Pulling her hand, Maria lead Mio to a certain area in wherever they were, causing an unknowing figure to walk into view as their eyes shined through the darkness.

"You can run, but it doesn't matter where you go... because no matter where you hide, I will find you!" They promised, their eyes glaring a bit.

* * *

**_~ 1 Month Later: Kuoh Town, March 30th_ **

The scene opened on a Saturday in a place that would best be described a Japanese City if a bit more in the countryside and a Town, specifically around a restaurant area with a poster that said [March Only! Satsuma Chicken!] on one of the brick pillars.

Inside one of the restaurants, the sight of a boy around High School age with brown hair and green eyes could be sitting at a booth table. Sitting across from him was his father, who looked the same as him, only he had a few scars, wore glasses, and had brown eyes.

"OK, explain to me why we're here and ordering this Oyakodon?" He asked, looking at his bowl of food.

"It's a limited time deal, eat it now or you'll regret it." His father answered.

His son just gave him a deadpan look.

"Seriously? You're way too old to be falling for that crap." He answered.

Either way, he picked up the bowl and started chowing down on his lunch.

"Hey... Issei? Didn't you say you had a thing for redheads?" His father asked.

"Hmm?" Issei blinked.

Taking a moment to register those words, a metaphorical question mark hovering over his head as it failed to ring a bell.

"You need to give me a bit more context there." Issei replied.

"You know, back when you were 10 and shouted what your favorite color was after seeing that one kid actress? Momo Momozono?" His father clarified.

"Redheads... redheads..." Issei thought aloud, humming slightly.

The metaphorical question mark immediately changed into an exclamation mark, causing him to remember those words. He did always have an unexplained fondness for that color for as long as he could remember.

"Yeah, I remember... wait a second, why are you asking me that out of nowhere?" Issei recalled, soon noticing the oddity of the question.

"Quite simple, because you might be getting a chance with one... that'll be living with us." His father answered, giving a near smirk at him.

Issei dropped his spoon at that, his face saying he was shocked, but his mind screaming in excitement.

* * *

10-minutes passed by, with Issei and his father now sitting on the same side of the booth as they waited for their female guest to make her appearance. Issei in particular covering his nose due to being next to his father's cigarette smoke.

"Weird, I wonder where she is? She should have been here by now?" His Father wondered aloud.

"I should have asked this the moment you told me, but now that I realize that... explain to me why you're doing this? It's out of nowhere?" Issei asked, raising an eye.

Puffing out some smoke for a bit, he looked the other way.

"It's a bit complicated and I promised her not to really talk much about it, but a friend I know told me this girl needs a home, so I decided to be her guardian. We're already about to move out of that old apartment, so I figured you should meet her and vice versa before we finally see the new house." His father answered.

"Still wish you let me know just a day in advance. It's happening so fast, I can't calm down." Issei replied, tapping his left hand on the table.

*"DING!"*

Looking at the door as the entrance sound rang, they saw it was just a man in a business suit. Issei groaned a bit in response.

"Why don't you go wash your face? Maybe that might help." His father suggested.

"Ugh... alright, see you in a minute." Issei sighed, getting up from his seat.

Walking to the bathroom, Issei released another sigh as he passed by a few waiters and patrons.

**_"My name's Issei Hyoudou, and that man you saw me with is my father, Jin Hyoudou. It's always been the two of us for as long as I can remember. While I don't know the story, my mother... died shortly after I was born. Things are tough under such a lifestyle, and without a mom? I just hope that things between me and this girl don't-"_ **

As he was about to finish that thought, he opened the bathroom door... only to gasp as he saw Mio pulling up her panties. That didn't last long as his eyes immediately moved to her incredibly gifted chest.

'Holy smokes, they're 105 cm!' Issei thought, somehow knowing her size by sight alone.

Issei sweated a little before seeing Mio finally blush, causing him to do the same before everyone in the restaurant heard them both scream in response, getting Jin's attention.

"Oh... that explains it. We missed her coming in." Jin sighed.

Mio immediately pulled up her panties before slapping Issei in the face, hitting him with enough force to send him flying onto the toilet seat.

"Idiot! Why didn't you knock!?" Mio screamed, covering her chest and skirt.

"Me? Why didn't you lock the door!?" Issei retorted, holding his red cheek.

"I did lock it!" Mio retorted.

The manager peeked in, making the two look at him as he gave an odd look over the situation, scratching his head.

"The door wasn't locked and I forgot to knock, yet she claims she did lock it." Issei answered.

"Eh? Didn't you see the notice the lock was broken?" The manager questioned.

Both of them tilted their heads.

"What are you talking about? There wasn't anything on the door that said that." Both of them replied.

The Manager's mouth frowned at that.

"Oh... guess I shouldn't have put it on the wall besides the door." He realized.

Hearing that made their eyes twitched as he walked away.

"Uh... any chance we can push this accident aside because that manager's an incident?" Issei hoped, sweating a bit.

"Fine, but only because I'm here to meet someone." Mio huffed, clearly still angry.

At that moment, Jin poked his head into the doorway, neither of them having heard him coming or at an angle to see him.

"Hey Issei, you done in there?" Jin asked, poking his head in.

Both of them turned their heads as they saw Jin looking at them.

"Father!"  
"Jin, it's you!"

Both of them immediately paused before looking at each other, with Mio quickly realizing who he was.

"Y-You're..." Mio realized.

"OK, this is totally awkward..." Issei remarked, blinking a bit.

Jin immediately and wisely. decided to wait back at the table.

* * *

As it began to rain outside, the three were seen gathered at the table, both teenagers having an uncomfortable silence over realizing who they were.

After a few moments passed, Jin sighed and decided to break the silence.

"We get it, you had an embarrassing situation in the bathroom. Get over it and introduce yourselves!" Jin exclaimed.

"Uh..." Both mumbled.

Jin immediately slammed his shoulder into Issei's side, making him wince.

"OK, I'll start... I'm Issei Hyoudou!" He greeted, his voice at a high pitch.

"And... I'm Mio Naruse." Mio greeted, slightly afraid.

"There we go! Also, thanks for coming to meet with us. Issei was excited to hear that a cute girl his age would be living with us." Jin chuckled, ruffling his head.

"DAD!" Issei screamed.

He immediately reached out at Jin, who held out a hand to block his arms. Mio briefly smiled at their familial spat.

"Oh, uh... I hope this isn't asking too much, but why are you staying with us, in the vague sense at least? Just need help or dealing with something personal?" Issei asked.

Mio looked surprised at that, as if Issei's response was something she never expected.

"Should have known you'd pick your nose into this. She's going through some tough times back home and ran off. Until things calm down and something more permanent is arranged for her, she'll be staying with us." Jin explained.

Mio saw Jin wave his hand a certain way only she could see, showing a bit of surprise before relaxing herself slightly.

"Oh... sorry, that was dumb." Issei apologized.

"Don't worry, I guess it's better you know so you don't ask questions at an awkward time." Mio reassured him, looking away.

There was silence for a bit.

"So, uh... how long until the rain stops pouring?" She asked.

Issei's cheeks puffed, trying not to laugh at that question.

* * *

Later that afternoon, Issei was seen standing in front of the new house that Jin had bought the day before. Looking at it, Issei sighed a bit, getting Jin's attention.

"What? You don't like it?" Jin asked.

"That's not the problem. It's just when I see it, it reminds me that she's not going to be here with us..." Issei answered.

Jin immediately realized what Issei meant, putting a hand on his shoulder.

"I know, you're not the only one who misses her. There are some days the grief gets so bad I can barely handle it." He reassured him.

Issei looked at him, raising an eye.

"That explains a lot about your smoking habits." Issei joked.

"Oh, wise guy, aren't you?" Jin snickered, giving him a noogie.

Issei laughed a bit.

"Funny enough, that's related to why I agreed to watch Mio." Jin admitted.

"Did she lose someone important to her?" Issei asked.

"No, more like she's having trouble understanding the value of a family. I'm hoping the fact we have a wound in our hearts due to your mom's death will help her understand." Jin explained.

"And maybe in turn, having a girl in the house will ease that wound." Issei realized.

Jin smirked at that.

"Yeah, it seems like there's a reason we were all brought together. Until we find out what that is? I want you to promise me you'll protect her, which means be considerate of what you do if you try to be a lover more than a brother." Jin stated.

"Hey, I'm not that bad!" Issei pouted.

Jin laughed at that, making Issei pout even more at his father's teasing.

"Hello! Aren't we going to take that picture now!?" Mio exclaimed.

"Hold your horses, I'm getting it ready." Jin chuckled, looking at her.

Jin unzipped a bag as he got a camera set up, with Mio moving over to stand by Issei's side as Jin prepared to take a picture. As this happened, Mio noticed Issei looking at her with a confused look.

"What's wrong?" Mio asked.

"Nothing, I just didn't expect you'd be smiling over this so easily after what you and my dad implied." Issei admitted.

"Hey! I happen to know how to smile just fine, thank you!" Mio replied, slightly glaring at him.

"I didn't say you didn't!" Issei exclaimed, holding his hands up.

And just like that, Mio smiled and gave a tongue and wink combo, making Issei realize what she did.

"Aw man, you little minx!" He stated.

"Don't blame me, you're the one who feel for this cat's little prank." Mio playfully retorted.

Jin soon set the timer, rushing over.

"OK, get ready!" Jin shouted, readying his smile.

Mio made a peace sign and smiled, while Issei gave a tooth grin and Jin got behind them and did the same (only as a smirk) with closed eyes.

* * *

The following morning, Issei was seen in his new room, sleeping on his bed as he drooled over a particularly wet dream he was having. As he laid there, someone walked into his room and sat on top of him with their legs spread out.

"I don't know how I got into this world, but I don't ever wanna leave it!" Issei giggled, still asleep.

"Wake up sleepyhead!" They shouted.

Feeling his dream getting interrupted, Issei fought to stay asleep... though he eventually lost, waking up to see none other than Mio's huge chest to his pleasure.

'Waking up to something like this? I don't care she interrupted my dream!' Issei thought, a heated blush on his face.

Blushing as he woke up, Issei looked to see Mio's smiling form looking at him.

"Good morning Issei, did you sleep well?" Mio greeted.

"Y-Yeah, especially with this kind of wakeup call! Although... is there any particular reason for it?" Issei answered.

"I thought a teenage boy would like to be woken up like this." Mio answered.

Issei gave a nervous chuckle, becoming a blubbering mess in response.

"Jin was right, you really are a pervert." Mio chuckled.

"H-he told you that!?" Issei exclaimed, his face paling in horror.

"You thought he wouldn't when you'd be living with a teenage girl? Speaking of which..." Mio countered.

Her face briefly glared at him.

"I'm willing to let you try flirting with me, likely in vain, but if you do anything to me like a horn dog would? Know that I'll kill you a hundred times." She warned.

"D-Don't worry! I'm a delightful perv, meaning I have morals! Worse I'd do is peak on you!" Issei confessed.

Mio blushed at that, giving him a look as he sweated a bit, looking to the side as he tried to think his next reply.

"Uh... but I won't do that either, because having a girl living in the house alone is a lot better than trying to peep!" He quickly replied, laughing worriedly.

"You're lucky that I'm actually willing to believe that, but watch yourself." Mio replied, squinting her eyes slightly.

Issei gulped and quickly nodded his head as Mio rolled off his bed, letting him get up as she walked out of the room. Once he got dressed, Jin was seen brewing coffee as he turned towards him.

"Hey Issei, I need you to go on a grocery run to fill this bigger pantry we have, so go out and get some food with Mio." Jin stated.

"Eh?" Issei blinked.

"You heard me, now get your bike ready and ride over there." Jin answered.

Issei groaned and motioned to Mio, who followed him.

"Is he like that often?" Mio asked.

"I can't tell if my father's just lazy or trying to have some harmless fun... or some other third option I might be missing." Issei answered.

Getting his bike out, Issei took his seat while Mio blinked in confusion.

"Uh... how am I supposed to sit on this?" She asked, looking confused.

"Another reason why I think my dad's trying to have a good laugh... you're going to have to hold onto me." Issei replied.

"Yeah, I'm starting to see what you mean there." Mio realized, sighing a bit.

Getting on the bike, Mio shook slightly before giving him a tight hug, making Issei release a sound of excitement as her breasts pressed against him.

'OK, saving this image to my brain!' Issei thought, breathing to stay calm.

And with that, he rode off towards the supermarket with Mio in tow, shouting loudly while he sped ahead before he got too overstimulated from her breasts touching his backside.

As they rode off, a girl with white hair looked their way, nibbling on a chocolate bar as opened her phone.

"Hey Rias." She began.

* * *

In a small building near a large school building, the sight of a girl with red hair like Mio's, only untied, could be seen sitting on a couch set by a chessboard. She had blue eyes and a similarly gifted figure, though not as gifted compared to Mio's.

"I see, thanks for letting me know she arrived safely. I'll set up the meeting when she comes to school tomorrow." Rias replied.

Hanging up the phone, Rias looked over the chessboard before her.

"Akeno, what do you know about Jin's son?" The redhead asked.

Hearing that question, a girl with an even more gifted figure than her friend, though still not as much as Mio's, turned to face her. She had long black hair tied in a ponytail tied by an orange ribbon, with piercing violet eyes.

"Hmm... let's see? Without double checking, I recall he's a Third-Year like we are in Class 3-B, has a reputation for being a pervert, and that he only lived with his father until recently. Is that adequate, or should I look under his files?" Akeno answered.

"Let me see those files. I'm curious to why Jin's never told him about his origins." Rias decided, feeling something was off.

Akeno nodded, going through them as Rias was left to her thoughts.

'Jin may be able to help her most of the time, but if he's absent and no one in my household can help her? I need to know why Jin is willing to put his faith in his son when he'll have little to no knowledge of his powers or the world his mother came from.' She thought.

Akeno soon handed the files to her, and a while after reading them... her eyes suddenly widened.

"Akeno?" Rias began.

"What is it Rias?" Akeno asked.

"Let everyone else know that the moment Issei Hyoudou becomes aware of the supernatural, I want him brought here." Rias requested.

"Understood." Akeno replied, bowing slightly.

Rias placed the files down on the table, surprised yet intrigued by what she read.

"How was he born as what he was? It can't have been natural for... actually, this is something anyone would struggle to do on purpose. Just how did it happen under any means?" She thought, wondering what the answer was.

* * *

Having bought a lot of food, enough for each of them to carry four bags, Issei and Mio stood outside the store.

"I'll be right back, let me go get the bike." Issei stated.

"Alright, though... why did you need two things of pepper yet only one thing of salt?" Mio replied, looking confused.

"Eh... hopefully you don't need to find out." Issei answered.

Mio looked confused, shrugging her shoulders as she decided to wait in place, though after a bit of waiting...

"Hey baby, you all alone?"

Turning around, she saw a group of thugs walking near her.

"You wanna go have some fun with us?" The lead thug asked.

She tried to walk away, but another put his arm around her, making her eyes shake as a certain memory began to well up and make her skin tremble.

_"I am why you are here... and you will obey me!" He screamed, his glowing blue eyes marking his silhouette as his oddly-shaped hand reached for her._

"Don't touch me!" Mio screamed.

Knocking his hand away, she backed up a bit and tried to keep a strong face.

"Try that again and I'll kill you a hundred times!" She threatened, glaring at them.

"You're going to kill us?" One of the thugs said.

"I'd like to see you try!" The lead thug challenged.

Mio felt a drop of sweat run down her face, knowing she was slowly being cornered due to the current situation.

'I can't use my powers against normal people, and even if I could... someone help me!' Mio begged, nearly crying.

The white-haired girl soon walked onto the scene, prepared to get involved, but before she had a chance to act?

"Hey, do you creeps have a problem with my friend?" Issei questioned.

All of the thugs turned around to see Issei on his bike, glaring at them with an angry look, while Mio looked relieved.

'Best... timing... ever.' Mio thought.

"Your friend? What kind of person would call a lame face as yours their friend?" The lead thug mocked, staring at him.

"Rather my lame face than your weird voice." Issei retorted.

"What the fuck did you just say about-" The thug screamed.

His words never finished as Issei slammed his bike's front wheel into his face, pulling Mio back as he did.

"You're dead!" One thug growled.

"You'll pay for that!" Another screamed.

At that moment, Issei pulled the extra pepper out of the bags, getting Mio's attention.

*"POP!"*

He immediately threw it, causing a cloud of it to scatter over the thugs.

"My eyes!" One thug screamed.

"It burns!" Another cried, holding his eyes.

They started sneezing as Issei pulled Mio onto his bike.

"Come on, let's get you out of here!" Issei exclaimed.

He immediately rode off as Mio hugged him tightly, riding away from the scene as the thugs kept wheezing, sneezing, and etc. from the pepper cloud that hit them.

As this happened, the white-haired girl smiled as she bit her chocolate bar again.

"He might be a pervert, but he's earned my respect." She stated before leaving.

As the duo rode away, Mio took a moment to register everything before looking at Issei, finally understanding why he had that extra pepper.

"Did you know those thugs would come after me?" Mio asked.

"No, but I heard there was a gang around the area, so I figured I should be ready. My father always says you should try to win a battle without violence." Issei replied.

At that moment, Mio laid her head against Issei, causing him to briefly glance at her as he saw her crying.

"Mio, are you alright?" He asked.

"I was so scared, seeing people like them here... thank you." Mio whispered.

"Like... who?" Issei questioned.

Mio paused for a minute, wondering if she should tell him the truth. Eventually, she decided not to be fully honest, but something close enough to it... at least until he knew what he really was.

"I think you should know the whole story... is there someone private we can talk?" She asked.

"Sure thing, and it's a place that makes me feel happy." Issei replied, looking to the left.

Issei quickly took a turn up the hill in that direction, with the sun beginning the set as he made a visit to a place he hadn't finished in a long time.

* * *

By the time the sun had gone down, they had made it.

"Where are we?" Mio asked, wondering where they were.

"It's somewhere special to me. I guess in a sense, you can call it my own special slice of Kuoh Town." Issei answered.

Putting up his kickstand, he walked over to the spot... which is when Mio saw it.

Before her was the entire sight of Kuoh Town, as if she was the pearl inside an oyster overlooking the full majesty of the ocean.

"Wow!" She looked at it all, smiling brightly.

"My dad and I found this place when we first moved here 12 years ago. I was initially hesitant about moving here, since it was like leaving everything about my mom behind. It was only after I got here that I realized no matter where I went, her memory would bring her with us." Issei revealed.

Mio looked at him, giving a sad look.

"I heard you mention this, how old were you when you lost her?" Mio asked.

"Just after I was born... never got to know her, except for this." Issei answered.

He pulled out a picture to show her.

Mio looked to see it was a very burnt photo, likely representing what Jin went through just to save it from whatever nearly took it away. Jin had slight burns over his hair and the left side of his body, with his right hand on Issei's head.

Holding the newborn Issei himself was his mother, with the only clear thing Mio could make out being her figure and her face, which had closed eyes.

"She looks like a kind mother... did Jin even tell you how she died?" Mio inquired, looking at her image.

"My dad may be lying or unaware of the full truth, but... this is the story he told me." Issei sighed, closing his eyes.

Looking up at the sky, the wind blew as if reacting to his story.

"She went out of country on business, only for misfortune to strike when she got caught in some kind of shooting... and end up as one of the casualties. I've never asked beyond that because I can tell how painful it was to lose her." He revealed.

Mio sniffled a bit, getting his attention.

"My mother's the only good memory of my family I have, yet it's still a small one." Mio replied, still crying.

"Oh boy, I'm already seeing a red flag here..." Issei realized.

Mio nodded her head, taking a deep breath before continuing.

"That memory was when she first had me as a baby, and it's a memory I think I only remember... because everyone else in my family is horrible. Even then, none of them compare to the man I'd call my  _father_." Mio revealed.

Issei's eyes widened at that.

"I... I don't know what to say to that. Although, now I get why those thugs got you so shaken." Issei realized.

"Yes, and worse... I don't even know why my mom's gone, or why I was left there. Did she pass away? Did they do something to her? Did she get away, but at the cost of being unable to leave me behind... or did she try to leave with me and pay the ultimate price?" Mio questioned.

"In other words, you don't understand family... because you don't consider them what a family is." Issei stated.

With that in his head, Issei immediately hugged her close.

"W-what are you?" Mio stuttered, a bit surprised.

"Maybe I can't be your boyfriend, and maybe... that's not what I'm supposed to be with you." Issei stated.

"Huh!?" Mio replied, looking confused.

"I think what I need to be for you is to be a big brother, even if only for right now or long-term." Issei smiled.

Mio blushed briefly before backing up a bit.

"B-Brother? You do realize that I'm not permanently living with you, right?" Mio questioned.

"So? When you're living with someone you want to protect, you're already family." Issei replied, petting her head.

Mio showed slight surprise at that.

"Family..." She repeated, staring a bit.

Issei turned at the setting sun, making Mio pause a bit before giving a calm smile.

'I guess... maybe it wouldn't be that bad to have a brother.' Mio thought, still smiling.

They stayed there for a moment, enjoying the peace.

* * *

Sometime later, both of them returned home, with Issei seeing his father preparing to leave for his job.

"What's got you going out so late?" Issei asked.

"Apparently there was something that happened downtown, should be back in about an hour at the latest. Hold down the fort until then." Jin stated.

Issei nodded before Jin drove off.

He immediately closed the door, only to hear a knock a few seconds later.

"Excuse me, is this the Hyoudou House?" A female voice asked.

Opening the door, he saw Maria standing before him, making him blink a bit.

"I'm a friend of Mio's... is she able to hear anything right now?" Maria whispered.

"No, she's in the bath." Issei asked.

"That's good. She takes long baths, so I should be able to talk to you about this without her walking in. May I?" Maria smiled.

Issei shrugged a bit, opening the door more to let Maria inside.

Maria soon sat herself at the table, while Issei took out bottle of Cola to offer her.

"Oh, sure. I'd like some." She replied.

Pouring her some, Issei soon sat across from Maria on the table.

"So, your name?" Issei asked.

"I'm Maria Naruse... and no, we're not related. I only know her because my family is the reason Mio's here." Maria answered.

"Let me guess, she took your surname to distance herself from her biological family?" Issei guessed.

Maria took a moment to sip her Cola before answering.

"Yeah, she's been through a lot. I'm one of only 5 people she could trust and call a friend after all she's gone through... and the others are all unable to be there for her." Maria confirmed.

"Did they help her escape her family?" Issei asked.

"They did, but if anyone had found out? I shudder at what would have happened to them... I can't even say if they kept their tracks clean." Maria confirmed, shaking her drink worriedly.

Issei still didn't fully get what was going on, but he at least could tell this wasn't a normal situation.

"I kind of get why my dad didn't say much, although... he still should have implied things better. If I had been aware a group of thugs risked triggering her, I wouldn't have let her come with me to the market." Issei sighed.

Maria showed surprise.

"Geez, did he try to make you bond over that or something? That guy can be the worst sometimes." Maria joked, smirking slightly.

"Yeah, he is... but I'm just like my father." Issei agreed, closing his eyes.

Maria looked confused.

"What I mean by that is I have my principles, and if Mio needs help? I'm willing to give it." Issei explained.

"That helps me feel relieved. It's also why I didn't want Mio here while I was talking about this, as otherwise she'd have been all  _I'll kill you 100 times!_ " Maria smiled, sounding witchy at the last part.

Issei snorted slightly, right as Maria finished her drink.

"Just two things I should say before I go? Don't try to be too guarding of Mio. She's stronger than she looks, and likely would have been able to handle those thugs if... well, if they had been anyone else besides thugs. Also, as much as she says she wants to understand family? I think she just wants to be loved in some way, so..." She continued, standing up.

Issei saw her walk to the door, turning her head before smiling at him.

"I wish you luck in opening her heart. Because I have a good feeling you might be able to do it, even if you're a pervert." Maria said, giving a cat-like smile at the end.

"W-Wait, how did you know that!" Issei exclaimed, blushing slightly.

Maria left before he could get an answer, making Issei slump into his chair from the embarrassment.

"Why do I feel that girl's going to be trouble if I keep don't keep my guard up?" He asked himself.

Realizing that he had to help Mio when she began school tomorrow, he decided to call it a night and went to bed, staring at the ceiling for a bit.

"I wonder if I should let people know the truth, or just say we're neighbors?" Issei wondered.

With that thought, Issei fell asleep.

* * *

Mio eventually left the bath and into the room she called hers in the Hyoudou House, sitting down on the bed as she remembered Issei's words from earlier.

_"I'm just like my father. I have my principles, and if Mio needs help? I'm willing to give it."_

_"When you're living with someone you want to protect, then you're already family."_

Mio immediately grabbed something from her back, revealing it was a brown picture frame with a cracked glass over an undamaged photo.

While she could see the picture without issue? Due to the cracks, anyone who tried to from her angle would only see her and Maria's faces, with everyone else in the image having theirs blocked off from the glare created by the moonlight.

"So, this is a family... right?" She asked herself.

A paper on her cabinet began glowing, making her look at it. She quickly listened for Issei's presence before locking the door. When that was done, she tapped on it, causing Maria to appear in the room.

"Hey there Maria." Mio greeted.

"Sorry if I came too suddenly, are you doing OK?" Maria asked.

"Yeah, I've settled in here fine... despite a few odd hiccups over the course of the day." Mio reassured her.

Looking to the side, Maria briefly glanced at the picture.

"Oh... sorry, I just..." She apologized, holding it to her chest.

"Don't be, I know you miss them. Just know we're doing all we can to try and get them away like they helped you escape." Maria reassured her.

"I hope you can." Mio replied.

Realizing she was still feeling down, Maria held out another picture frame to her, getting Mio's attention as she saw the one Jin took earlier.

"Don't forget, me and all of them aren't the only ones here for you. Issei and Jin are now part of your life. Not only that, but Issei said it himself, he's your big brother now." Maria reminded her.

"But I'm not sure if I should even involve either them, especially Issei..." Mio replied.

"Jin already told me... he doesn't know what he is, or the real reasons for why Jin's watching over you." Maria responded back, making a slightly sad face.

She took a deep breath, changing it to a smile.

"But that's also why I think it matters you still keep him close. Right now, you need every ally you can get, and I'm almost certain... that he'll be more important than you realize." She reassured her.

"Why do you say that?" Mio asked.

"Think about it. Jin took you in, despite how your existence alone threatens nearly two decades of hiding the truth from his son. It's obvious to me he doesn't care if his son finds out. I think you should consider that, because maybe in his eyes... he knows his son is who you need most." Maria answered.

Letting that sink in, Mio looked at Issei's image on the picture, and smiled a bit... unaware of her slight blush.

"Ooh, have you fallen for him already?" Maria teased.

Issei was sleeping when a huge scream and banging sound was heard, making him briefly open his eyes... but then close them moments after, still too tired to fully wake up from it.

Inside Mio's room, Maria was seen on the ground with a swelling on her head, courtesy of Mio's fist.

"Just a simple tease made you hit me?" Maria sniffled.

"Now I remember why Jin didn't want you living here, you perverted Succubus!" Mio screamed.

Nearly stabbing her finger through the same paper that brought Maria into her room, the silver-haired Succubus was quickly forced out in the same manner. Only then did Mio finally go to sleep.

* * *

Within the same building Rias and Akeno could be seen in, the white-haired girl was reporting to the crimson beauty.

"I see, thanks for keeping an eye on her, Shirone." Rias smiled.

"I'm just glad that I didn't have to get involved thanks to him. If only he wasn't such horn dog all the time, he might actually get a girl to like him." Shirone remarked.

Akeno briefly giggled at that.

"Speaking of those two, did you notice anything beyond that while scouting around town?" Akeno inquired.

Shirone went silent at that.

"I sensed a couple of Fallen Angels around the area, they got pretty close to the perv." Shirone revealed.

"Fallen Angels... do you have any ideas of what they were doing?" Rias questioned.

"No, but they got close enough they suddenly ran away. Not sure if it's because they knew who his father was... or something else." Shirone shrugged.

Rias hummed a bit, rubbing her chin.

"Hmm... let's have our Familiars broaden our horizon for now. If there is something he has, then we need to know what it is in advance." Rias decided.

"Understood." Akeno and Shirone replied.

Shirone held out her hands to make a white cat appear, while Akeno's hands puffed out smoke that created six Imps, specifically three pairs containing a red, green, and blue duo.

Rias soon held out her hand as a spherical Bat formed from her hands.

'Now, the question is who else will make a move... and who's daring enough to go after them without caring about the consequences?' Rias thought, keeping her worry internal.

That thought stayed in Rias' head as their Familiars spread out across town.

* * *

Taking a puff of his cigarette, Jin was seen by the fountain in the park was his eyes looked around, trying to look for something.

"Not sure if I'm honestly just too on guard or not, but if there was someone here... then I applaud them for being smart enough to realize what a mistake it is to try facing me." Jin remarked, smirking slightly.

Walking in another direction, the sight of a Fallen Angel could be seen shaking as she hid behind a tree trunk. She had two wings, an outfit that was best described as a Dominatrix outfit mixed with a bikini, long black hair reaching to her waist, and purple eyes that were dilated from pure fear alone.

'Damn it! The brat I was keeping my eye on is his son? Forget him, I'm not risking a guarantee that both will become our enemies, not when I'm so close!' She thought.

Taking the chance to fly off, Jin briefly glanced back as he saw her leave, thought letting her fly off since he realized the vast difference in their power.

He instead opened his phone, deciding to make a call.

"Hey, it's me." Jin replied, holding the phone to his ear.

* * *

In some village deep in the mountains, the sight of various children using wooden swords to spar could be seen, watched over by some adults with strong lean builds.

However, it was inside one particular hut that a man was answering a call.

"Are you certain? Then why not... wait, she could do wait if tried that? Then I guess it makes sense for her to be with you." He answered.

While that was going on, some of the older children in their teens could be seen, with one in particular turning their heads as they listened.

"Understood, I'll call the Vatican and ask for volunteers here." He agreed, nodding his head.

Hanging up the phone, the man turned as he saw the one listening walk closer, along with a few others that had caught on after they had.

"Hmm... interesting, looks like we have more than a few." He said, smirking a bit.

While this was going on, one particular person could be listening within some kind of prison, giving an interested chuckle at what he could see from his closed eyes.

"Just what is the War God up to right now?" He questioned.

"Would you like to see firsthand?" A deep voice questioned.

Turning in surprise, the boy looked to see a figure appear via a magic circle without setting any alarms as they stared at him.

"Oh, and just what kind of offer are you giving me?" He inquired.

Upon saying that, the boy's eyes opened, showing the menacing orbs that were hidden beneath them.

* * *

Morning finally came, with Issei yawning as his usual alarm clock woke him up, changing into his school uniform while still somewhat asleep. As he did, he walked towards the bathroom to brush his teeth.

"What... is... this!?" Mio exclaimed.

"Hmm?" He blinked, turning his head.

Issei spit into the sink before walking towards her room, where he saw Mio looking at some of her school outfits. Noticing how her Gym Uniform and School Swimsuit were clearly the kind perverts would gawk at, evident by Issei's brief nosebleed.

"I... see you got your school uniform... and related outfits." Issei stated.

Mio looked at him, blinking a few times in confusion.

"What's school?" Mio asked.

Issei could only stare at that, turning his head around before taking a deep breath.

"Hey dad? Can you-" Issei asked.

*"LOCK!"*

Issei froze as he heard Jin lock his door, leaving his eye to twitch as he now had to explain what school was to a clueless teenage girl.

"My father did this, so please don't kill me for what I'm about to tell you!" Issei begged.

"Uh... I think I'm more terrified by what you said than anything..." Mio replied, gulping slightly.

Issei whispered everything to her ear, and then Mio felt her eye twitch before she suddenly rushed towards Jin's door, slamming on it with her fists as he held his hand against it.

"Open the door Jin! I'm coming in there and then I'm killing you a hundred times, do you hear me!?" Mio roared.

'Is it wrong that I want to laugh at this?' Issei thought.

Realizing this wasn't going to do any good after another minute, and worried Mio might hurt herself, he pulled her away from the door.

"Calm down. Look, I have to go to school too, and most of it is as crappy as you think." Issei stated.

"Is there an upside to this?" Mio asked.

"Yes, it being that we both have to suffer over the same thing." Issei confirmed.

Mio paused for a bit, then released a sigh.

"Alright, I'll go... but I'm still hitting your father later." Mio agreed.

"Hey!" Jin exclaimed.

Issei chuckled a bit, soon waiting by the wall as she got changed, thinking over a few things as he waited.

"Hey Mio?" Issei asked.

"What is it?" Mio replied.

"People might find out we're living together, and that might cause a scene considering my reputation there, so... think we should just come clean with that or make some kind of story to prevent any rumors about you?" Issei answered.

"Uh... what kind of story would even fly under all that?" Mio inquired.

"Not exactly sure, but going with how I'm acting like a brother to you... we could just say we're cousins?" He suggested.

Taking a moment, Mio shook her head.

"That seems too far-fetched, why not just say we're old childhood friends that view each other as siblings?" Mio suggested.

"Yeah, that idea sounds better." Issei agreed, nodding his head.

Finally getting her uniform on, Issei turned as Mio opened the door and showed him how she looked in it. Issei gasped as he saw her, merely giving a warm blush.

"What? Do I... look bad?" Mio asked, turning away bashfully.

"Not at all, you look... kind of cute in that." Issei confessed.

Mio blushed at that before looking away, coughing as she grabbed her bag.

"Uh... come on, show me the way to this... Kuoh Academy?" Mio quickly asked.

"Right, follow me!" Issei replied.

Grabbing his hand, Mio let out a slight yell as they headed off to school, with Jin opening the door as he watched them leave.

"Well, guess this is where it all starts." Jin remarked.

He went into the kitchen to brew himself some coffee.

* * *

Eventually arriving at Kuoh Academy, Mio blinked a few times before briefly glancing to the side, then blinking back at the main school building. Issei quickly took notice of this.

"Uh... Mio, are you alright?" Issei asked.

"Huh? Oh, I'm fine. Just surprised by how... big it is." Mio replied, struggling to keep a poker face.

Buying her words, he shrugged before walking ahead.

"Come on, I'll lead you to the faculty room." Issei decided.

"S-Sure, let's go do that and anything else we need to do." Mio agreed, still struggling with her poker face.

They headed inside, though as they did? A few students noticed the two together.

"T-There's no freaking way!" A boy exclaimed.

"He had to have done her homework or... wait, is that girl new!?" Another boy stated.

"What is happening here? Is he supposed to be cool now!?" Murayama asked.

"Yes, and I think it's working!" Katase answered, holding her close.

From a distance, Rias was seen looking out of her window on the second floor of the old school building as they walked inside the school.

"I hope Jin knows what he's doing." Rias stated, looking worried.

* * *

Walking to the halls as they headed to the Faculty Room, the sight of a nervous Issei and quiet Mio could be seen walking past all the students giving them their mixed reactions over how the former was walking with someone like the latter.

'Makes me wonder how my class will react when they see this...' Issei thought.

"I'm guessing that everyone's reactions have justification in some manner?" Mio questioned, looking at him.

"N-No comment..." Issei answered.

Mio sighed at that, which is when the two finally made it to the faculty room. Opening the door, Issei cleared the throat, looking to where his teacher was.

"Excuse me, I'm here to help a new student?" He stated.

At that moment, a beautiful young woman with long silver hair and aqua colored eyes turned to them.

"Ah, you must be Mio Naruse. I'm Ms. Weisse, your homeroom teacher." She greeted, holding out her hand.

Issei blinked at Mio's sudden silence, lightly shaking her shoulder.

"Huh?" Mio blinked, looking at him.

"I'm guessing how young she looks got your off-guard? Well, that's because she's actually our age." Issei explained.

"Wait, she's only 18!?" Mio exclaimed.

"I'm much smarter than my appearance might tell you." Rossweisse explained.

Mio had to pinch herself just to confirm she was awake.

She quickly realized that it hurt when she did.

"Ow..."

Rossweisse soon stood up, picking up a red binder.

"Well, let's head on over to class now, shall we?" Rossweisse suggested.

* * *

Issei headed into his classroom, with Mio waiting outside as instructed due to being a new student, with the bell eventually ringing to signal class had started.

"Everyone? Before we begin class today, I should let you know that we have a new student." Rossweisse announced.

That got everyone's attention as their teacher turned towards the door.

"Come on in." She smiled.

"R-Right..." Mio replied, sweating a bit.

Walking into the room, Mio immediately caught everyone's attention, including a few of the students who had seen the duo outside. She quickly wrote her name on the board before looking at everyone.

"Hello there, my name is Mio Naruse..." She greeted the class.

Issei sweated as he felt everyone staring at him.

"So, does anyone have any questions for Mio?" Rossweisse asked.

"I do. Tell us, why were you and this pervert walking to school together!?" A boy asked, pointing at Issei.

Issei gulped a bit.

"Well, that's because... I'm living with him!" Mio answered, very loudly.

Issei felt the sound of glass breaking in his mind, counting down from 3.

"WHAT!?" The girls exclaimed.

"ISSEI!" The boys growled, looking at him.

Issei began sweating more, shaking a bit.

"Calm down everyone. Before you maul Issei, let's hear her out. Especially since he may have little involvement in this." Rossweisse stated.

Everyone sat down, still glaring daggers at Issei.

"I have... complicated circumstances, and Issei is a childhood friend of mine, kind of like a big brother. Due to this, his father is acting as my guardian for the foreseeable future." Mio explained.

Hearing that, everyone relaxed a bit. Lucky for Issei, his reputation as a pervert was tied to the students knowing he had boundaries, so the sibling excuse managed to fly.

"Now then, let's begin class, shall we?" Rossweisse suggested.

* * *

In the same unknown place Maria helped Mio escape from, the sight of a certain figure's glowing eyes could be seen as he stared at another silhouette.

"It's time for me to reclaim Number 720185, but I can't risk directly involving myself. With that in mind... how would you like to cause some chaos by helping me out?" They offered.

"Tell me, would this help our cause in ruling Hell?" The silhouette asked.

The owner of the glowing eyes laughed as his way confirming his question.

"Very well, then I accept for the glory of the Moderate Faction." The silhouette confirmed, giving a dark and quiet chuckle.

Smiling at him, the figure with glowing eyes laughed.

"Good, now go and show the Devils of this Kuoh Town the consequences behind protecting my greatest Super Devil... Zolgear." They smiled.

The silhouette figure was soon revealed as a dark-skinned Demon with horns and gold marks on his head.

"Oh, I intend to." Zolgear confirmed.

* * *

**Alright, there we go with the new first chapter. Hopefully this went well. Also, I'll say this version will use Basara in some way, but Issei's got the main protagonist role because of something in Shinmai/Testament that's also in DxD... yet can't really mix together. For Issei himself, he'll be channeling Basara in a sense, hence why he has the maturity we see from him in the latter DxD novels.**

**Anyways, this chapter's set up a few characters' eventual appearances, while also showing some of the villains. We've also alluded to the secrets tied to Issei and Mio that play a major role in the story line. Maria also didn't move into the Hyoudou House with Mio because... well, I'm pretty sure that Issei would have no problem with Maria's Succubus antics like Basara does.**

**Since I know some will ask about this? In DxD, the Devils are still called Demons on occasion, so for this story? Devils are just the most common kind of Demon, with a few other kinds that serve their government in various ways, Maria being one example. I'll go into that more in the next few chapters, but the main point is Devils are the most numerous and powerful kind of Demon in this story's world.**

**Before I close things off? I've been made aware by a few friends that crossovers are a lot trickier than fanfics based on one series, and since this is my first, I might contradict something in this story at least once without realizing it due to the two sources I'll have to occasionally check in-between. As such, if anyone sees anything like this? Let me know so I can fix it/them.**

**Until next time everyone, and stay awesome! ^^**


	2. Chapter 2

**Notes for the Chapter:**

> Before this story's discontinuation on FFN, I was working on Chapter 2, and after some thought?
> 
> I decided to give some sort of conclusion by making a summary of the events that would have happened had I continued, since I know a few people were excited for this story.  
> \---  
> Issei's harem (from how my plans would have gone) would be:  
> Rias, Mio, Chisato, Irina, Celis, Koneko, Kuroka, Akeno, Rossweisse, Zest, Maria, Verrine, Yuki, Kurumi, and Asia.

**Hey everyone, we're here for Chapter 2, and now that we are? I'd like to make an important announcement about the story. This story's ending and planned length has been decided, which I'm estimating around 25 to 35 chapters as of right now. This is mainly because the story of Shinmai/Testament is much shorter, and with Mio being a major character _and_  a major plot point, I think it's best to make the story around that length.**

**How this effects the harem? I'm still not sure, but I'm going to look over how the Shinmai/Testament girls are able to quickly develop feelings while also avoiding being rushed or static for any girls who don't already have a romantic interest in Issei/Basara from the start, as I don't want anyone to seem like they suddenly just fell for Issei out of nowhere.**

**Something I'd also like to bring up due to one review making me realize that I may have not made this as clear as I'd like for everyone? This second attempt at the story isn't trying to mix Issei and Basara together like before. I've simply overlaid part of Basara's life into Issei's life for reasons related to spoilers, which is why I said Basara will show up somehow.**

**Anyways, this chapter is where the DxD cast will finally get their turn in the spotlight. Better yet is there's another big surprise I've got set to appear in this chapter. There's also a little something from the Shinmai/Testament side that will be appearing in this chapter, and while it's small, it's one I'm pretty sure that those who know it will love once they see it. I think this all fits well with how this is the chapter is where everything starts.**

**Now, time for me to stop talking and get this chapter started!**

* * *

**()**  - Albion Talking via the Divine Dividing

 **[]**  - Ddraig Talking via the Boosted Gear

 **{}**  - Consciousness of any other Sacred Gear Talking

 **〖〗**  - Voice Speaking through a Magic Circle

 **【】**  - Voice made by an Announcement or through an Announcer

『』 - Electrical Voice or Machine Speaking

 **「」**  - Insert Song Beginning or Ending

* * *

**_ Chapter 2 - Welcome to the Club _ **

Class ended for the day at Kuoh Academy, with Mio currently talking with four of the girls in her class.

Two of them were shown to be Katase and Murayama, while the other two were a blonde with long curled hair named Shihi Aikawa, and the other had short green hair named Chika Sakaki.

"So, that red hair's natural? That's incredible!" Chika exclaimed.

"Are you somehow related to Rias Gremory?" Shihi asked.

Mio gave an awkward chuckle at that, while Issei watched from his seat, wondering if he could leave her to herself for awhile or stick around.

'Well, at the very least she's socializing with some potential friends.' He smiled.

Finally deciding he could trust her by herself for now, he prepared to walk out the door, but when he tried to leave...

"Issei, you bastard!"

*"SMACK!"*

*"WHAM!"*

Everyone turned around as they saw Issei fall onto his back, his left eye black and his right cheek swollen as they saw two male students had punched him in the face! One of them had his hair in a buzz cut and had huge ears, while the other had glasses and short shaggy hair.

"How dare you hide that hot piece of ass from us, you're a traitor to all perverts!" The buzz cut gut shouted.

"Now where's this hot number!?" The glasses freak questioned.

Mio paled while looking scared at Issei's current facial horror.

"What... the fuck... is happening?" She asked, clearly sensing danger from the two.

"That's Matsuda and Motohama. They're perverts like Issei, only without any filters." Murayama whispered.

"Don't get close to them, all they do is jerk off." Katase warned.

Hearing this, she quickly gained an angry expression, letting off an aura that most of the students only noticed when someone managed to tick off Rias or Sona.

"Both of you, out of the way... now!" Mio demanded.

They turned to see Mio, and briefly showed excitement... right until they heard her crack her knuckles.

"Now, tell me why you punched Issei." She demanded.

"Uh, well... the thing is-"

Both of them were cut off as Mio twisted their arms around, surprising some of her classmates.

"I catch you doing this again, I'll kill you a hundred times." Mio warned.

"Y-Yes ma'am, as you say! We promise!" They answered in a panic.

She dropped them to the ground, then knelt towards Issei as he began to lose consciousness.

"Issei? Issei!?" She called.

And then he blacked out, only hearing her faded shouting before it faded away.

* * *

_Various Dragons were seen roaring as they blasted their various breathes across the land, razing everything and everyone in their path as they did._

_"Burn it all to the ground! Destroy everything!"_

_"Destroy! Plunder! And Repeat!"_

_The Dragons continued their massacre, many screaming as they were burned to a crisp, but as one prepared to gobble a young girl..._

_"Guh!"_

_Holding its throat, the Dragon screamed in pain before it was cut into skewers and its blood sprayed everywhere. Its fellow kin turned in surprise before something dashed past them, causing another hundred to spray a bloody mess as they met their ends._

_Stopping in place, the culprit was revealed to be a tall and slim man with unkempt brown hair that jutted in all directions and green eyes that glowed slightly. He also wore a silvery armor with glowing green and red spots across it._

_"You? We'll annihilate you from this world, so prepare to die!" The Dragon's Head roared._

_The Dragon's black and gold eyes lit up before it fired a powerful dark flare, which swallowed up the area he was standing in as he screamed in pain. From a distance, a pair of woman with red hair showed faces of horror._

_"No... get up ***STATIC*** , please get up!" The first woman shouted._

_"Don't break your promise!' The second woman shouted._

_Hearing their voices, the brunette warrior shouted as he rose his weapon, pushing through the attack as he clashed with the powerful Dragon before him._

* * *

Issei suddenly gasped as he woke up, panting heavily at the dream he just head.

"What... was that?" He asked himself.

"Glad to see you're alright, especially since both of those punches could have given you a concussion." A female voice stated.

Turning around, he suddenly blushed at who owned said voice.

She was a stunning woman with a voluptuous figure, with breasts and a butt bigger than Mio's (his eyes measuring the former at 108 cm), having sexy black hair that reached hip-length and green eyes emphasized by a beauty mark under the left and red glasses.

Her attire consisted of a single earring on her left ear, a green knitted turtleneck, a tight black mini-skirt along with her cross garter motif stockings, a pair of black high heels, and a white doctor coat to show her position as the school's nurse.

'Oh, my god! Did I get killed and get sent to Heaven with a sexy Angel milf as my reward!?' Issei thought.

Good thing he had a bloody nosy due to the perverted duo's earlier blows, as his he got a nosebleed from his hormones going into overload. Then again... the nurse was sexy enough that she likely knew and paid it little to no mind.

"U-Uh... are you new? I don't remember seeing you in the nurse's office before?" He asked.

"I am, this is my first day. I'm Chiasto Hasegawa." She confirmed before introducing herself.

Issei chuckled at that, turning his eyes away.

"Yeah, my best friend just started today, and she's also facing sexy pro... I mean getting used to all per... I mean unique stuff here." Issei mentioned, sweating a bit.

Mio groaned as she walked into the room.

"Smooth... real smooth Issei." She stated.

"I-I don't know what you're talking about Mio, I wasn't talking about her tits... I mean how sexy she's... aw, damn it!" He stuttered.

Chisato giggled a bit, getting their attention.

"Your friend here mentioned two boys punched you because of jealousy. In a sense, you could say you've made most of the boys in this school your enemy." Chisato replied.

"That doesn't sound good..." Issei mentioned.

"Oh no, it just means be aware of the quantity and quality of your allies. Both need to be weighed... when you consider your options." She explained, pausing to briefly adjust her glasses.

She stepped out for a moment, leaving the two to blink as they kept staring at the door.

"That was... different?" Mio remarked.

"Yeah, though I definitely like that nurse better than her predecessor." Issei replied.

"Because she's hot?" Mio questioned, giving him a deadpan look.

"Uh... OK, guilty as charged, but that's not the only reason. She seems pretty nice too. However, most of all... despite I just met her, it feels like I know her somehow?" He answered.

Mio looked at Issei in confusion, wondering what that could mean.

A sudden knock quickly interrupted their trains of thought, making them turn to see Rossweisse by the door.

"Sorry, but can I ask the two of you to come with me?" She asked.

* * *

_Following Rossweisse's request for them to follow her, Issei and Mio meet up with Rias and the members of the ORC, with her peerage consisting of the initial members, Rossweisse as her Second Knight, Kuroka as her Mutation Bishop, and Zest as her Second Rook. They explain things to Mio, though have Issei help Akeno with tea to keep him absent, knowing it isn't the best time for him to be aware of his origins just yet... though even they have no knowledge of the strange dream he had._

_Asia arrives in Kuoh Town around this point, and the Fallen Angels proceed with their plan, simply making themselves more secretive since Raynare managed to find out Jin is onto them. Because of this, Freed is kept away from killing anyone, with the normally insane priest admitting even he's smart enough to know Jin would kill him as easily as swatting a fly if he got on his bad side. It matters little in the end when Asia and Issei make contact, and he's drawn in after they try to reclaim him._

_With his choice to join in the rescue mission, Jin tells him about some of his heritage, though not what he is specifically, and helps him get ready. Most of all... Mio decides to admit the truth about what she is, revealing the number she was called by Zolgear's contact, which is actually her other name. It turns out she's none other than one of millions of Devils that were made by Hades through the once lost source of demonkind. Specifically, she's one of the three Super Devils he managed to make, and the strongest of the three. Her "mother" was that very source itself, and not an actual mother._

_During the attack, Issei is cornered by Raynare and her trio of friends from canon as he finds Asia, who all gang up on him. He's overwhelmed despite the training Jin gave him earlier, and eventually overwhelmed... though Asia calls out to him, and he finds the strength to summon the power he was born with... the True Longinus! With one strike, he kills all three of them, but immediately passes out from the strain of using the powerful Sacred Gear without any training._

_After this event, things die down as the aid from the Hero Tribe's village and the Vatican finally arrives and transfer into Kuoh Academy. The former group consists of Yuki, Kurumi, and Takashi; while the latter group consists of Irina, Xenovia, and Celis. Issei doesn't recognize Yuki, Kurumi, Irina, and Celis at first... until Yuki makes him grab his butt, which helps him remember after she mentions he used to hug her like this. (Which many wish they didn't hear after she says it.)_

_Later on, Yuki explains a few things to Issei about Mio, and why Hades' creation of her is a problem if he gets his hands on her. She mentions while they are asked to help defend her... if the worst-case scenario would to happen, they will have to kill her, and when Issei calls her out on this? She reveals this was Mio's request, not theirs, as Mio has had little to live for besides friends of her that had to stay behind, likely suffering for helping her escape. Before leaving, she tells him if he wants to prevent this, he needs to give Mio a reason to live and keep Hades away._

_This is when Lars appears in the night and causes trouble, leading to many monsters hunting after Mio to either reclaim her under Zolgear's command, or steal her powers so Hades can just transfer it to a more loyal Devil among his army. Eventually, Issei asks Mio why she doesn't fight, and she reveals her powers are just too dangerous to use in a human settlement the size of Kuoh Town. It doesn't take long for Issei to find out when he's injured by Lars, making her flee out of guilt._

_Mio runs into Lars and tries to fight back, and he eventually tries threatening her, but she doesn't fall for it. When he questions her reasons for not trusting him, Mio asks him "what happened to my friends?", a question he realizes is likely what she expects it to be. Irina and Xenovia show up to help, but their efforts are for naught against Lars' power, which unfortunately sets Mio's powers off and risks the destruction of Kuoh Town, but Issei arrives and manages to activate his Balance Breaker, using it to negate her rampant energy._

_Once this happens, Lars tries to flee and warn Zolgear... only for Balberith and Verrine to reveal they've managed to escape Hades, forcing Lars to meet Issei and be put into a hostage situation. The end result means he'll falsify his reports in exchange for his life. Knowing he's been cornered, he's forced to accept the terms. Meanwhile, Mio goes to talk with Rias and Maria about a strange feeling that she's had since Issei saved her, which Maria has a good feeling about._

_Rias herself starts to wonder about Issei, noticing how close he's gotten to everyone and how much he's now involved in her life, showing some scenes in between where he's helped her out for fairly minor reasons shown via brief flashbacks. During this, she fails to notice a monster based on Viser try to attack her, leaving her open... until Issei manages to save her. After making sure she's OK, Issei helps her get home, which ends with Rias feeling a strange warmth in her chest... unaware of a red bird spying on her._

_It isn't long before Riser appears, along with the trouble of his engagement to Rias, forcing the need for their Rating Game if she wants to be freed. Everyone decides to help her train, with Jin offering to keep an eye on Kuoh Town in their absence. While all the training is fruitful, even having a larger peerage than in canon ends with the same results of a loss without Asia's healng or Issei's Boosted Gear to eliminate all but Ravel and Yubelluna near the end, but when Rias is shown being brought to tears? Issei snaps._

_Breaking into Hell on his own, he crashes the engagement party, with Sirzechs making his offer out of sheer intrigue for his ability to reach the party despite everything that should have kept him away. Despite all of Riser's efforts, actually giving Issei a challenge, he's ultimately unable to win when Mio and Rias cheer for him, unlocking a power that renders Riser unable to use his healing flames, which finally allows him to do enough damage to win._

_After the battle ends, his harem officially begins when Rias and Mio kiss him, admitting their feelings. (The former due to freeing her, and the latter realizing how she feels after how far he pushed himself) Once they return home, Issei ends up at Chisato's apartment, where she reveals her identity as Issei's cousin before seducing him. While he enjoys it, Issei is left confused until she asks about if he ever had a strange dream since he had met Mio, shocking him._

_It turns out he was dreaming about one of his past lives, the legendary Dragon Slayer known as Basara Toujou (who was the inspiration for Rias to name Koneko and Kuroka), that saved the world when the Dragon race threatened to enslave and/or destroy all life. Apparently, the real reason their kind is low in numbers is because only 10% of them wanted to live alongside the many races, forcing them and the other races besides Humanity to create the True Longinus and wipe out the remaining 90% that cared for nothing else._

_There were many women he cared for, and all of them have reincarnated in the present day, meaning the lookalikes to Mio and Rias were such. Past lives that meet again in another era often fall in love again should they meet, depending on what happens, with Chisato being one of them. She had regained her memories some time after he was born, and mentions one power that ended this ancient conflict came from Basara ending Crom Cruach, the Banishing Shift, which can erase things._

_This is why Issei inherited the True Longinus and managed to defeat Riser's healing ability, he managed to erase it with the Banishing Shift, though the difference is Issei's version is only temporarily due to its power being diluted over his many reincarnations. Once this is all finished, Issei then asks why she never helped his group out in the past, with Chisato revealing she's not allowed to help him. She then apologizes, saying she can't say anymore until Jin reveals the truth, though doesn't say what kind of truth it is._

_After too many issues, Zolgear finally decides to take action himself, swallowing Kuoh Town in a monster that knocks out anyone without any supernatural ability. During this instance, Zest reveals her origins as being a creation of the very Demon in question, and says he's as dangerous as Hell's current leaders. Everyone is forced to work together to save the town and it's people, facing many of Zest's clones, while rescuing some of their allies like Chisato and Jin, but the monster's heart is immune to the Banishing Shift and everyone else's attacks._

_However, everything falls for Zolgear when Jin says Issei can break it, shocking him as he reveals only someone with the blood of an Angel and a Devil can break it, a union that's forbidden due to the current stances of Heaven and Hell... which can only mean one thing. However, knowing that Zolgear is a bigger threat, Lars appears to finish him off. Questioning why he would, Lars reveals he wanted to end him since he killed his caretakers in a Demon orphanage when he was a mere child._

_Once he leaves, and realizing the cat's out of the bag, Jin decides it's time for Issei to know the truth about his heritage. Most of all, he reveals Issei that he's a Human/Angel/Devil hybrid... because he actually has two mothers! Moving to somewhere quiet, he shares his story from where it began, during the war between the Devils and the Heroes. He was on the front lines when he met the second child and the daughter of Lucifer, better known as Sapphire._

_They fought heavily, forcing everyone else away from each their respective sides to avoid causing unnecessary deaths, tearing up enough of the battlefield that a third party was forced to intervene. Said being was none other than Raphaeline (who takes DxD Raphael's place), one of the Ten Angels that were made deities when they succeeded God, after his physical form was lost in the Great War from long ago. She tried to stop their battle, only to join in after they forced her hands._

_In doing so, they ended up causing a dimensional fault that threw them into the dimensional gap, a prison where the last of the savage Dragons that Basara wasn't able to defeat after exhausting his strength were thrown in, all still alive and eager to kill anyone and anything that enters. Realizing they would have to work together to survive and escape, they managed to fell the remaining Dragons and get out, an experience that caused both women to fall in love with him. Before long, their sexual tension hit a peak and they all shared their love, making Sapphire conceive Issei._

_Realizing the problem of returning with a child? Raphaeline transferred the child into her womb, as a child between a Hero and a God was allowed, but it wasn't long before the demonic energies of the child leaked out and alerted her fellow deities in Heaven. Threatened with death, Jin stepped in and begged for them to be spared, no matter what it cost. Deciding to show him mercy for felling the Dragons in the Dimensional Gap, allowing its existence to no longer be needed, they would spare both of Issei's mothers... if they promised to never interact with Jin or their son._

_However, they did allow each a chance to spend a day with the boy, who would lose his memories of meeting them once it was over. Issei is hurt, but Jin states if he hadn't agreed to it, he'd been responsible for the deaths of the three people he loved most. It was also the only hope he had they could be a family one day, because if Heaven and Hell were to one day make peace, they would finally revoke that rule and allow both his mothers to return._

_Soon, the Kokabiel arc happens, which merges with the Demon Council's threat (being the equivalent of the Old Satan Faction) that pushes both sides to the brink as an exiled priest takes many of the Church's Holy weapons to aid in their plans, along with the Heroic Spirits once belonging to the Hero Clan, who received them from original God and highest Angels long ago. Pushed to a limit, Issei merges his two powers to create his Chaos mode and defeat the the allied forces of Kokabiel and the Demon Council._

_This incident finally forces Heaven and Hell's leaders to realize they can no longer keep going like this, and consider a summit where they may finally make peace with one another. During the set up of this meeting, Issei is granted the right to meet both of his mothers', giving him a sense of closure as he spends time with both. He swears the summit will succeed so they can all be together again, but at the same time... Hades (who takes the appearance of Testament's Belphegor) gets wind and decides to take his last stand._

_Gathering his forces, the last of Mio's friends, Gressil and Sonneillon, are revealed to be double agents and now Super Devils as they join him. On the day of the summit, they all attack, preparing to wipe out everyone as Issei and his friends fight against them. In the process, Hades reveals part of Crom Cruach's soul and merges with it (becoming Chaos in appearance) and overwhelming everyone... until Issei finally unlocks all of Basara's latent powers in his Chaos form, destroying all of Hades' strength at the cost of losing the Banishing Shift forever._

_Deciding his death would be too light a punishment, everyone decides to keep Hades alive, but sealed and fully conscious of the fact of everything he did failing and leaving him to this fate. With the battle over, the summit ends with the Angels, Fallen Angels, and Devils making peace due to the events and everyone fighting together proving that unity between them is possible. Most of all, Sapphire and Raphaeline are finally allowed to live with their son and the man they love._

_The story ends with an epilogue showing Issei's future, having married all his harem and having one child with each like in the future shown in the EX novel._

**Notes for the Chapter:**

> And that's it.
> 
> If I ever feel like it, I may type up some of the scenes that I really wanted to make, so keep an eye out for this story possibly going past 2 chapters.


End file.
